Shirley Douglas, the impassioned Canadian activist and veteran actress who was mother to actor Kiefer Sutherland and daughter of medicare founder Tommy Douglas, has died.

She was 86.

Sutherland announced his mother’s death on Twitter, saying she succumbed to complications surrounding pneumonia on Sunday morning.

“My mother was an extraordinary woman who led an extraordinary life,” said Sutherland.

“Sadly she had been battling for her health for quite some time and we, as a family, knew this day was coming.”

A native of Weyburn, Sask., Douglas worked with famed directors including Stanley Kubrick (“Lolita”) and David Cronenberg (“Dead Ringers”), and won a Gemini Award for her performance in the 1999 TV film “Shadow Lake.”

She also tirelessly supported a variety of causes throughout her life, including the civil rights movement, the Black Panthers and the fight to save public health care, pioneered by her politician father.

In 1965, Douglas married Canadian actor Donald Sutherland, with whom she had two children before they divorced — twins Rachel, a production manager, and Kiefer, who became a film and TV star in his own right.

Douglas also had another son, Thomas, from a previous marriage.

In a 2009 interview with The Canadian Press, she admitted that being away from home for lengthy periods of time to pursue acting was hard on her children, but said she knew it would make her a better mother in the end.

“Our jobs, we move around a great deal … and that is the reality that my children grew up with — is being left, and not happily,” said Douglas, who used a wheelchair in recent years due to a degenerative spine condition that caused her severe pain.

“You either have to decide you’re going to be guilty about it and not do it, or that you are going to do it and that you will be, in the end — and I hate to use it as an excuse — but that you’ll be a better mother than being home bitter that you aren’t allowed out.”

Born on April 2, 1934, Douglas showed an early interest in the arts as well as politics as she journeyed on the campaign trail with her father, who became premier of Saskatchewan, a federal NDP leader and a socialist icon.

She attended the Banff School of Fine Arts and went on to study at the Royal Academy of Dramatic Art in London, England, where she acted in theatre and TV and participated in anti-nuclear marches.

In the ’60s and ’70s, while living in California, Douglas campaigned against the Vietnam War and protested for various politicial and social causes.

She also helped to establish a fundraising group called Friends of the Black Panthers. Her support for the group brought controversy, though — she was refused a U.S. work permit and arrested in 1969 on conspiracy charges of possessing unregistered explosives. The courts eventually dismissed the case and exonerated her.

Douglas’s other activism included co-founding the first chapter in Canada of the Performing Artists for Nuclear Disarmament.

She said she never worried whether standing up for what she believed in — even in the days of the so-called Hollywood black list — would hurt her acting career.

“I think to live your life you have to live it, and if you see something that offends you morally or any other way you have to follow that and take it up,” Douglas told The Canadian Press, noting she also had support from many fellow actors and filmmakers.

“I know a lot of McCarthy-ite victims. It was hard for them but really they had no choice. And when you have no choice and you see something, it’s like if you see a child going to be run over by a car — you grab the child.

“And for me, many things that I see wrong are as obvious as grabbing a child and so what else would you do?”

Douglas, who lived in Toronto since ‘77, was nominated for two other Geminis: in 1998 for her leading role in the series ”Wind at My Back,” and in 1993 for starring in the film “Passage of the Heart.”

She was also an Officer of the Order of Canada, an inductee into Canada’s Walk of Fame and had an honorary doctor of fine arts degree from the University of Regina.

Her other screen credits included the film “Nellie McClung,” in which she played the title role of the famed Canadian activist. Other TV series in which she appeared included “Street Legal,” “Road to Avonlea,” “Corner Gas,” “Degrassi: The Next Generation” and “Robson Arms.”

In 1997, Douglas got to work onstage with son Kiefer in the Tennessee Williams play “The Glass Menagerie.”

Perhaps her biggest role, though, was as a champion for medicare.

Douglas would speak of the importance of a universal health-care system at virtually any opportunity and lobbied government officials and fundraised for the cause.

She was also a national spokeswoman for the Canada Health Coalition lobby group and was involved in the Toronto Health Coalition and the Friends of Medicare Toronto.

“Let us never forget that the federal government is the guardian and enforcer of the five principles of the Canada Health Act: universality, accessibility, portability, comprehensiveness and public administration,” she said in a statement on behalf of the Canadian Health Coalition during the 2011 federal election campaign.